Editing Warhammer 40,000/7th Edition Tactics/Space Marines (section)

===Mechanised Assault===
When I'm talking mech, I'm talking armour over flesh, AV versus T, and tank treads versus boots on the ground. This is a lesser-played style that has both been nerfed and strengthened in different ways thanks to 7th Edition. With the Hull Points system, every vehicle becomes more fragile, meaning mobility and cover are the most important things for keeping your vehicles alive. In addition, no longer being able to move 12" and disembark cripples your mobility and ability to react on the fly to different situations over long distance - you now have a 24" deadly threat range with a squad inside a Rhino. To compensate, you gain the ability to go flat out and move up to 18" in a turn with a transport - though this is of limited use.  This tactic has also been improved by 7th edition, thanks to vehicles only exploding on a penetration roll of 7 and thanks to the Double demi company with free razorbacks. 

Unfortunately, this is not an easy playstyle. It's brutal, and often even when it does work, the firepower you leverage against your opponent is not sufficient. It is, however, not entirely doom and gloom. If you run a mechanised list you should seriously consider the White Scars Chapter Tactics with Khan as a HQ. 

The advantages they confer make your army go from sub-competitive to just below tournament-level (tournament level if you're both lucky and good, or happen to use the aforementioned Double Demi).

White Scars CT give your mechanised infantry Scout, which they absolutely *need* in order to be as good as they should be. It gives massive amounts of flexibility to your infantry and the potential for an alpha strike that leaves your opponent in checkmate after the first turn. 

How, might you ask? Take your Mechanised Infantry and deploy them as close to the enemy as possible. Before the game, scout 12" towards the enemy. You now have a few options.

# Move 6",disembark 6", be in their deployment zone, and fire. This gives you your alpha strike that, with the right units, can annihilate your opponent's deadliest unit or cripple part of his force.
# Move 12", flat out 6". This allows you to compensate if your opponent bunches up and option 1 is not viable. Sometimes, having your men ready to react (remember you'll get a potential 6" move and 6" disembark instead of just the former) and staying inside the metal box is the best course of action. 
# Move 12", pop smoke. Use only if your opponent either had nothing that is worth risking getting out of the boxes to eliminate or if your opponent has a strong gunline with lots of anti-infantry firepower that you can't cripple.

Alternatively, you can do none of the above and outflank. This can be a risky but effective way of delivering an alpha strike or capturing an objective without being struck by fire. 

Now, the real question is what to put in your transports? As previously mentioned, a mech SM list suffers greatly from sometimes not being able to leverage enough firepower. This should be your primary concern. 

Tactical Squads should probably not be taken with full numbers at 10 men - unless you plan to abuse combat squads for a very specific use. Reason being, you do not want heavy weapons except Grav Cannons. There is no reason to maximise bolters. Heavy weapons will rarely get to fire effectively and now cost you points out the ass. Taking a special weapon and combi-weapon should be considered mandatory. Do not give this squad melta guns. Leave that to the other elements in your army, because you want your Tacticals to leverage as much firepower against infantry or MC's as is humanly possible, and have enough duplicates that losses do not necessarily mean defeat. 

*Grav Guns are a matter of debate. They are flexible against vehicles (if you can get off enough shots) if you do encounter them, if you do dig in the extra shot is invaluable, and they get the extra shots at longer range than a Plasma Gun. If there's a Daemon Prince or CC unit they even reduce their initiative to 1, giving you better odds if you get dragged into a CC. However, they suck hairy balls against anything that isn't wearing power armour or better, and are utterly useless against buildings. 
*Flamers are exceedingly good at quickly wiping anything weaker than Marines off of objectives. They also provide some effective overwatch. Even power armoured units will feel the heat due to the sheer number of wounds a flamer can throw at a unit. Their biggest drawback is being absolutely worthless against MCs. 
*Plasma Guns are good in that unless a rare high-toughness MC like a Wraithknight appears you'll be wounding on good rolls all the time. They don't suffer the drawbacks of Salvo (half range if you move, for instance) and have a greater maximum range than Grav weapons. 


You should take at least one Sternguard squad tooled up with enough firepower to destroy (not just cause medium damage to) a unit. Using #Option 1 they can pull off some kills that win games. They are the guys that are going to hunt the nastiest, shittiest, pain-in-the ass targets that your bolters and Tacticals can't handle. 

It's for this reason that they should have combi-plasmas or gravs. You might not survive into the following turn, as they will be a very high priority target, so what you shoot at needs to die. 4-5 combi-weapons should be sufficient. Heavy Flamers are worth considering, and the squad should not end up having more than 7-8 men. Do not tool up the Sergeant unless it's with a combi-weapon. 

There may be other units that perform this role almost as well - you may want to consider them, too. The effectiveness of the Grav-Gun Bikers make them one of
THE BEST units in the codex, and any bike-mounted IC makes them troops - yes, this means Techmarines, Chaplains and Librarians too.

These two units should form your core. In the end you should have a minimum of 3 mechanised squads, preferably 4. With the strong anti-infantry and anti-MC capability they provide you can look to everything else. 

*Units you may want to consider include:
**Tri-Las Predators or Devastators with Lascannons. If shit luck strikes and your Sternguard fail or don't do as well as you plan, these guys are Plan B. If there's tanks to kill, these are the units that will be your best counters.
**Storm Talons or possibly Storm Ravens. They provide AA and additional firepower on the fly (no pun intended) where its needed. In a pinch they can also serve as backup AT. '''Edit:''' Death from the Skies nerfed the hell out of these units, making them best suited for dealing with ground threats. For real AA, you need Hunters, Stalkers, Stormhawks, or Flakk Missile Devs, with an emphasis on ground-based AA to deal with threats you can't handle in the air, like Crimson Hunters.
**Land Speeder Storm Scouts. Deep Strike disruption, cheap scoring, can tackle weaker troops, and you can take a heavy flamer for free at 40 points, which negates the need for flamer Tacticals. 
**Assault Squads with flamers and either a drop pod or rhino. Cheap and (in certain circumstances) incredibly effective. 
**Grav Gun Bikers, for the same reasons as Sternguard. Or a Bike Command Squad. 
**Grav Cannon shooty Centurions in a Drop Pod or Land Raider. Bear in mind that they're shit in melee so if they get caught they're boned. That's why you attach a beatstick/bullet sponge IC. But now the White scar's CT affects them so you now have hit and run Centurions.